1. Field of the Invention
This invention relates to improvements in a multilayer microelectronic circuit which is used to be directly mounted on the surface of a substrate, and more particularly to the technique for forming a signal line of the circuit to be in a disconnected state relative to the substrate.
2. Description of the Prior Art
It is well known that a multilayer microelectronic circuit constructed and used as a resonator or the like is produced by laminating a plurality of dielectric layers and patterned electrodes. An example of such a multilayer microelectronic circuit J is constructed in a structure shown in FIGS. 7 and 8 to form an electrical circuit, in which an input line I', an output line O', grounding lines G' and signal lines NC' are formed at the side surfaces S1' of the multilayer microelectronic circuit. The input line I' is connected with an input section of the electrical circuit. The output line O' is connected with an output section of the electrical circuit. The grounding lines G' is connected with a grounding section of the electrical circuit. The signal line NC' is formed to connect various sections of the electrical circuit. This multilayer microelectronic circuit is directly mounted at its mounting surface (or lower surface) S2' on the surface of an electrical substrate K as shown in FIG. 8 where the upper surface S3' is observed. The mounting surface (or the lower surface) is shown in FIG. 7.
In the multilayer microelectronic circuit, all the above-mentioned electrically conductive lines are formed reaching the mounting surface as shown in FIG. 7. Additionally, as shown in FIG. 8, the input line I' is connected with a patterned signal input contact Ib' of the substrate K. The output line O' is connected with a patterned signal output contact Ob' of the substrate K. The grounding lines G' are connected with a patterned grounding contact Gb' of the substrate K.
However, drawbacks have been encountered in the above-arranged conventional multilayer microelectronic circuit, as set forth below. Each signal line NC' is adapted to connect the various sections of the electrical circuit formed inside the multilayer microelectronic circuit and therefore is required to be disconnected from the various patterned wiring of the substrate K. Accordingly, the substrate is formed on its surface with a section .alpha. to which the signal line is electrically connected, and a generally circular insulating section .beta. for insulating the section .alpha. from electrical contact with other sections such as the patterned grounding contact Gb'.
Thus, with the above-discussed conventional technique, it is required to perform a process for forming the insulating sections .beta. at the surface of the substrate K in order to prevent the signal lines NC' of the multilayer microelectronic circuit J from being electrically contacted with the patterned wiring of the substrate K. This degrades the serviceableness of the multilayer microelectronic circuit.